The Laboratory of Neurobiology, Sch. of Med., Med. Sci. Campus, U.P.R., serves two main functions. First, it offers access to the Caribbean marine fauna, as well as to many invertebrate species which inhabit the rain forests of Puerto Rico. Second, it provides, to both Puerto Rican and visiting biomedical scientists, a research facility with laboratories and instrumentation to allow projects to be conducted in the field of anatomy, ultrastructure, electrophysiology and toxicology of nervous and other excitable tissues. The immediate objectives of the Laboratory of Neurobiology change often, reflecting the interests of associates and visiting scientists. Current projects include: Neuromuscular physiology of Onychophora; induction of excitability in crustacean muscle by chemical modification of membrane proteins; pharmacology of nicotinic endplate receptors. Also the Lab. of Neurobiol. provides other departments and laboratories with specimens and toxins.